Machine for machining tapered studs



April] 11, 11951 J. M. APPLETQN 9 9 MACHINE FOR MACHINING TAPERED STUDS Filed Aug. 6, 1945 s Sheets-$heet 1 a l I 45 INVENTOR. JOHN M. APPLETON Aprifl W, 1951 J M. APPLETON MACHINE FOR MACHINING TAPERED STUDS s Sheet-Sheet 2 Filed Au 6, 1945 IN VEN 7013.

JOHN M. APPLETON April 10, 1951 J. M. APPLETON 2,543,137

MACHINE FOR MACHINING TAPERED STUDS Filed Aug. 6, 1945 3 Sheets-Sheet 3 HI I: i ;INV.ENTOR.

' BY JOHN M. APPLETON Aifiorr. eyd

Patented Apr. 10, 1951 MACHINE FOR MACHINING TAPERED STUDS John M. Appleton, Muskegon, Mich., assignor to Continental Aviation & Engineering Corporation, Muskegon, Mich, a corporation of Virginia Application August 6, 1945, Serial No. 609,164

4 Claims.

The present invention relates to the threading of studs or the like and particularly to threading by rolling a suitable blank between suitable straight dies.

Among the objects of the invention is means by which said studs may be tapered for a portion of their length.

The threading of studs by rolling in the threads is quite old and the tapering for a portion of their length is also old but heretofore it has been necessary to use step dies which are expensive, I

difiicult to make, of short life, and many different sets of dies are required due to the length of thread required.

Another object of the present invention is, therefore, to obtain the desired taper while making use of a conventional die without the step.

Still another object is means which may be adjusted to provide a tapered portion of two, three or more threads as desired.

Other objects and advantages will readily occur to those skilled in the art upon reference to the following description and the accompanying drawings in which Fig. 1 is an end elevation, with parts in vertical section, of the active parts of the thread rolling machine.

Fig. 2 is a plan view of the same.

Fig. 3 is an enlargement of the sectioned portion of Fig. 1, showing the parts in a different position.

Fig.4 is an elevation of the valve control, indicating its action.

Fig. 5 is a partial end View of the machine.

In the drawings, there are shown only those parts of the threading machine which act directly on a stud to be threaded, it being understood that a suitable base or frame and means for actuating the movable parts will be used. These latter being no part of the invention, are not being shown.

As in conventional machines for threading, a suitable blank I is rolled between a pair of straight dies II and I2 to press the threads into the blank l9. This is done by holding the die 52 against longitudinal movement while the die I I is carried on a slide i IA which is conventional except as will be described later.

The die I2, however, instead of being mounted in a fixed holder, as is usual, is carried in a cradle member I5, having its rear face are shaped with the center of the arc at a point between the two dies and approximately at half the height of the dies.

This cradle member I is supported in a corre- 2 sponding curved seat in the base It and is held against displacement by end plates I! screwed to the ends of the base' I6 and curved concentrically with the cradle and seat, the ends PM of the plates Il extending over the ends of the cradle l5 and in suitable curved seats I5A therein.

The central portion of the seat for cradle I5 is cut away to provide a recess IQ for thereception of a rearwardly extending arm 26 fixed to or formed integrally with the cradle I5, the recess I9 being bridged by a plate 2| which overlies the arm 29, sufficient space being provided to iermit a small vertical movementof the arm. This vertical movement is adjustably limited by suitable stop screws of which three are shown. The screws 22 are fixed in the plate 2 I, extending therethrough and acting against the arm 20 or a suitable inserted hardened button 22A.

The stop screw 23 is fixed in the arm 20 and extends loosely through plate 2| above which the nuts 23A act as an adjustable head to limit the downward movement of arm 29.

The cradle I5 also is provided with an upwardly extended boss 25 having a bore 26 extending horizontally therethrough from front to rear at the ends of which the boss is faced with hardened washers or plates 21.

Through the bore 26 extends a rod 38 of somewhat smaller diameter than the bore and carrying at the end of the latter a collar 3I, which is provided with an angular face 3IA contacting the adjacent face plate 21, the apex line of the angle being horizontal and extending across the plate 21 at substantially its center.

These collars 3| are provided with suitable set screws 3IB to prevent rotation but are fixed against longitudinal movement on the rod 30 by, in one case, a suitable shoulder 32 and, in the other case, nuts 33.

The rod 30 extends rearwardly and is functionally a part of the piston rod extending into a doubleacting pressure cylinder 35 to the ends of which lead conduits 36 and 31 from a valve 38 operable by a vertically movable stem 39. Valve 38 is carried on a suitable stationary portion 4!] of the machine and the stem 39 is actuable upward by a plunger 39A mounted in a suitable bracket MIA, the plunger 39A carrying a roller 39B acting as a cam follower and prevented from turning by means of a suitable screw 403 in bracket 40A. Downward movement of the plunger and stem is accomplished by suitable spring means (not shown).

Carried on the movable die holder I IA is a cam so positioned with respect to the die that, at a 3 suitable point before the end of die travel, the sloping surface 45A of the die strikes the follower 39B and lifts the valve stem. The return movement of the slide of course permits the downward movement of the valve stem.

In the operation of the machine, fluid, preferably air, under pressure passing through valve 38, enters cylinder 35 through conduit 31 and maintains the die I2 in the position of Fig. 1. As the operation of threading nears completion, the cam 45 acting on valve 38 causes the pressure in cylinder 35 to be transferred from the rear end to the front end through conduit 35 and thereby the cradle l5 and die I -2 to be tilted as in Fig. 3.

Return movement of slide I IA permits the valve 38 to restore the pressure to conduit 31. and return the cradle to the position of Fig. l.

I claim:

1. In a threading machine, alongitudinally reciprocable member, a stationary member,. said members having faces normally parallel to each other, but in spaced relation, a threading die mounted in each of said faces, said dies being in opposedparallel relation-and spaced from. each other, means for moving an edge portion of one.

of said dies toward the other die and means actuated by said reciprocable member during the reciprocation for causing such die movement.

2. In a thread rolling machine having a reciprocable member and a stationary member, a die mounted in each of said members, one of said dies having a fixed mounting, a cradle member carrying the other of said dies, said cradlebeing rockable on an axis parallel to the movement of reciprocation, and means actuated by said reciprocable member to cause said cradle to assume a position wherein its die is tilted with respect to the-other die.

3. In a thread rolling machine, a pair of dies of which one is mounted for reciprocation past the other, means for mounting one of said dies, said means consisting of a die holding member having an arcuate rear face, the aXis therefor being parallel to the line of reciprocation, an armate seat for said member, and means for moving said member on said seat, said moving means comprising a fluid pressure cylinder and piston with the piston operatively connected to said member, a valve adapted to admit pressure fluid alternately to the ends of said cylinder, and valve actuating means carried by the reciprocable die carrying element.

4. In a thread rolling machine, a reciprocable slide member, a die mounted thereon, a fixed member, a die carried by said fixed member and held normally in opposed relation to the first die, mounting means for said second die comprising a member partially rotatable about an axis parallel to the line of reciprocation, means for effecting such partial rotation comprising a fiuidmotor, a control valve therefor and a cam for actuating said valve, said cam being mounted on said reciprocable member adjacent the end of its movement of reciprocation.

JOHN M; APPLETON.

REFERENCES CITE!) The following references are. of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 760,301 Berry May 17, 1904 1,968,296 Hiester July 10,1931 1,915,667 Hiester June 27; 1933 2,145,587 Draper Jan. 31, 1939 2,331,443 Von Zelewsky et a1. Oct. 12, 1943 2,350,190 Quick May 30, 1944 2,367,398 Hoern Jan. 16, 1945 2,369,318 Sirp etal Feb. 13, 19.45 

